The present invention relates to computer interface devices. In particular, the present invention relates to a keyswitch base for computer keyswitches.
Keyswitches are used in a variety of computer interface devices, such as keyboards, gaming devices, stand alone switches and mouse switches. For example, a typical keyboard includes a top case, a bottom case, and one or more keyswitch bases which are mounted within the top case. Each keyswitch base includes an array of one or more square or round silos for supporting an array of one or more corresponding keyswitch plungers. An array of sensors are mounted to the back of the keyswitch base such that actuation of a keyswitch plunger changes the state of a corresponding sensor. This change in state is detected by the system to which the keyboard is connected. Several types of technologies have been used for sensing actuation of a keyswitch plunger, such as direct electrical contact, capacitive, electromagnetic and optical technologies.
Keyboards have traditionally had a flat design in which all keyswitches lie in the same key plane. Manufacturers are now beginning to offer ergonomic keyboards having multiple sets of angled key planes. For example, the Microsoft NATURAL KEYBOARD.RTM. input device has a top case which defines three sets of key planes that are not parallel to one another. Three keyswitch bases are molded as separate plastic parts and then installed in the corresponding key planes of the top case.
With traditional silo designs, the direction of pull between the two halves of the injection molding tool must be aligned with the direction of keyswitch operation (i.e., normal to the keyswitch base). Since each keyswitch base lies in a different and non-parallel key plane, separate injection molding tools, separate assembly steps and separate alignment steps are required for each keyswitch base. The inventors of the present application have found that with traditional silo designs, the only way to integrate the keyswitch bases and the top case together as one plastic piece would be to add moving mechanisms such as slides and lifters to the injection molding tool. However, adding slides and lifters has the disadvantage of increasing tool complexity, tool fabrication costs, maintenance costs, cycle times and part costs. These add to the product cost of goods sold ("COGS") through increased inventory and assembly times.